The present invention relates to apparatus for removing gaseous components and/or solid impurities from a gaseous fluid flow and, more particularly, to apparatus incorporating scrubbing means which serve to wash away any gaseous or solid impurities present in the gaseous fluid flow.
Gaseous fluid flows frequently contain impurities both in the form of gaseous components and solid particles which must be removed prior to further processing and use of the fluid flow.
Various apparatus are known by which gaseous fluid flows, such as coal gas or other gases, are washed or scrubbed to remove such impurities. One type of such apparatus includes a frame structure in which are accommodated an inlet connector through which the gaseous fluid flow is charged into the apparatus, a discharge connector through which the purified fluid flow is discharged from the apparatus, scrubber means for washing the gaseous fluid flow and a connector for conducting a scrubbing liquid into the apparatus so that the same contacts the gaseous fluid flow.
In practice, the gaseous fluid flow frequently contains solid impurities in such large quantities that their separation from the fluid flow before the latter reaches the scrubber means is desirable. Thus, it is common under usual conditions to purify a gaseous fluid flow using a wet scrubber wherein the gaseous fluid flow is conducted into a frame portion of a separator, i.e., into a fluid tank or reaction chamber, wherein intimate contact between the scrubbing liquid and the gaseous fluid flow is attempted to be maximized. At least part of the coarser fraction of the solid matter impurities will separate from the gaseous fluid flow during this scrubbing phase and remain in the separating tank.
However, it is most desirable to separate the greater part of the solid matter impurities from the gaseous fluid flow prior to the scrubbing phase while in a dry state and attempts have been made to achieve this action in either a settling chamber or in a cyclone separator. This technique is advantageous in that the quantity of solid impurities which are carried into the scrubbing liquid is minimized so that the amount of sludge which is created during the scrubbing phase and which must be removed from the apparatus will be maintained at a minimum. Moreover, since a blower is usually provided after the scrubber, this technique also advantageously reduces wearing of the blower. A droplet separator generally is provided following the blower and depending upon the particular application may be constituted by a grille, a set of gratings, droplet separators of the cyclone separator type, various rotating and round towers, and the like.
In conventional scrubbers known in the art, the blower is usually similar to a conventional centrifugal blower. A so-called disintegrator type blower is also known in the art into which the gaseous fluid flow with its impurities together with the scrubbing liquid are directed. Such designs require a high power input from a drive and, moreover, the blower is subject to a high rate of wear.
In scrubbers of the venturi type, the gaseous fluid flow together with the impurities contained therein are accelerated in a venturi section to obtain a high velocity and at the same time the scrubbing liquid is introduced into the accelerated fluid flow. After passing through the venturi section, the gaseous fluid flow with a reduced flow velocity is acted on by a droplet separator where the impurities will serve as crystallization nuclei.
So called S-wave scrubbers have also been utilized in connection with the purification of gaseous fluid flows. In such arrangements, the gaseous fluid flow together with a scrubbing liquid flows through an S-wave shaped slit to enter into a free space from where it is directed into a blower. In such arrangements, there is no separate droplet separator, the separation of droplets taking place in the free space after the S-wave scrubber and before the blower. However, a risk exists in this arrangement that supercondensing moisture may be entrained with the gaseous fluid flow with droplets then being flung outwardly into the surrounding areas.